Systems and methods for transferring data

ABSTRACT

Disclosed are systems and methods for transferring data. In one embodiment, a system and method pertain to configuring a first device to send data, touching an external contact of the first device to an external contact of a second device, and transmitting data from the first device to the second device via the touching contacts.

BACKGROUND

[0001] Previously, data was only transferred between devices using wiredconnections. For instance, multiconductor cables may be connectedbetween two devices to transfer data from one device to the other. Morerecently, however, more sophisticated methods for transferring data havebeen devised. For example, various wireless communication protocols,such as Bluetooth™ and IrDA (Infrared Data Association), have beendeveloped that are intended to simplify communications between devicesby doing away with the need for wires or cables.

[0002] Although wireless communications do facilitate communicationwithout wires or cables, contrary to the intent behind the creation ofwireless schemes, wireless communications can create confusion and/orirritation for the common device user. For instance, if two devices, saya desktop computer and a personal digital assistant (PDA), areBluetooth™-enabled, the devices may automatically begin communicatingwith each other when one device is brought into proximity with theother. Although such automated connection may be appreciated by moresavvy users, the typical user may be confused as to why or how suchcommunications began. Furthermore, such a user may be concerned aboutwhat types of communications are being had between the devices and, insome cases, unintentional data transfer from one device to another mayoccur (e.g., synchronization of email messages). Therefore, suchautomation can result in a perceived lack of control for the user.

[0003] Aside from the above-noted concerns, wireless communication isunattractive from a cost standpoint. Specifically, the radio frequency(RF) transmitting and receiving components typically used in currentwireless communication schemes add expense to the devices that comprisethem. Moreover, relatively large amounts of power are required to drivesuch components. Although power consumption may not be of great concernfor devices that are connected to a home or office alternating current(AC) supply, power consumption is very important for portable devices.Yet another limitation of wireless communications is the availability ofbandwidth that may be used to transfer data, as well as the speed withwhich such data can be transferred using that bandwidth.

SUMMARY

[0004] Disclosed are systems and methods for transferring data. In oneembodiment, a system and method pertain to configuring a first device tosend data, touching an external contact of the first device to anexternal contact of a second device, and transmitting data from thefirst device to the second device via the touching contacts.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The disclosed systems and methods can be better understood withreference to the following drawings. The components in the drawings arenot necessarily to scale.

[0006]FIG. 1A is an embodiment of a system with which data can betransferred between devices.

[0007]FIG. 1B is a detail view of a device shown in FIG. 1A.

[0008]FIG. 2 is an embodiment of the architecture of the devices shownin FIG. 1A.

[0009]FIG. 3 is a schematic diagram of an embodiment of an integratedcircuit that can be used in the architecture of FIG. 2.

[0010]FIG. 4 is a flow diagram illustrating an embodiment of a methodfor transferring data.

[0011]FIGS. 5A and 5B illustrate the touching of contacts of two devicesfor the purpose of transferring data.

[0012]FIGS. 6A and 6B provide a flow diagram illustrating an embodimentof a method for transmitting data from one device to another device.

[0013]FIG. 7 is a flow diagram illustrating an embodiment of a methodfor receiving data from a device.

DETAILED DESCRIPTION

[0014] As identified in the foregoing, sophisticated data transfermethods, such as wireless communication, are intended to simplify datatransfer for the user, but create other problems for the user, one ofwhich being confusion and/or irritation in regard to communications thatautomatically occur between wireless-enabled devices. As is described inthis disclosure, however, highly efficient and intuitive data transfercan be achieved by providing both the sending and the receiving devicewith an external contact that, when touched to another such contact,facilitates delivery of data from the sending device to the receivingdevice.

[0015] In such a communications scheme, relatively large amounts of datamay be transferred between devices in a seemingly instantaneous mannerfrom the perspective of the user. Moreover, this transfer speed can beachieved using relatively simple circuitry, thereby reducing both devicecost and device power consumption.

[0016] Disclosed herein are embodiments of systems and methods fortransferring data. Although particular embodiments are disclosed, theseembodiments are provided for purposes of example only to facilitatedescription of the disclosed systems and methods. Accordingly, otherembodiments are possible.

[0017] Referring now to the drawings, in which like numerals indicatecorresponding parts throughout the several views, FIG. 1A illustrates anembodiment of a system 100 with which data may be transferred betweendevices. As indicated in the figure, the system comprises a first device102 and a second device 104. In the example of FIG. 1A, both devices102, 104 comprise a digital camera. As will be apparent from thefollowing discussion, however, each device 102, 104 may generallycomprise any device that can either store and transmit data, or receiveand store data. Therefore, other examples for the devices 102, 104include a desktop personal computer (PC), Maclntosh™ computer, notebookcomputer, tablet computer, personal digital assistant (PDA), mobiletelephone, and the like. In some embodiments, one or both of the devices102, 104 comprise a portable and/or handheld device so as to facilitatesharing of data between such devices without the need for data cables orwireless communication.

[0018] Irrespective of the particular configuration of the devices 102,104, each is provided with an external contact 106, with which data canbe transmitted to and/or received from another device. As shown mostclearly in FIG. 1B, which illustrates a portion of the device 102 ingreater detail, the external contact 106 of the embodiment shown in FIG.1 is a male contact that extends outwardly from the body of the deviceso as to facilitate convenient touching of the contact to anothercontact (of like or different configuration). Therefore, as indicated inFIGS. 1A and 1B, the contacts 106 may be formed as metal nubs or othersuch protuberances. Although male contacts are illustrated in thefigures and have been identified explicitly herein, alternativearrangements are feasible. For instance, in situations in which onedevice typically will be the transferor of data and the other devicetypically will be the transferee (i.e., recipient) of data, thetransferring device may have a generally male contact and the receivingdevice may have a generally female contact, or vice versa. In any case,the contacts 106 are normally positioned so as to facilitate touching ofthe contacts together.

[0019] In addition to the external contacts 106, each device 102, 104may also include an indicator 108 that is used to convey information asto the transfer of data from one device to the other. In the embodimentof FIGS. 1A and 1B, this indicator 108 comprises a light-emittingelement, such as a light-emitting diode (LED), which is provided on thebody of each device 102, 104 generally adjacent the contact 106. Use ofthe indicators 108, and the manner in which they convey informationregarding data transfer, are described below.

[0020]FIG. 2 illustrates an embodiment of the architecture for either ofthe devices 102, 104 shown in FIG. 1A. Therefore, in the followingdiscussion, it is presumed that the device described is capable of bothtransmitting and receiving data. More specifically, illustrated is anexample architecture of a digital camera that is configured tofacilitate data transfer. Therefore, for the remainder of the discussionof FIG. 2, it is assumed that the device is a “camera.”

[0021] As indicated FIG. 2, the camera 102, 104 includes a lens system200 that conveys images of viewed scenes to one or more image sensors202. By way of example, the image sensors 202 comprise charge-coupleddevices (CCDs) that are driven by one or more sensor drivers 204, orcomplimentary metal oxide semiconductor (CMOS) sensors. The analog imagesignals captured by the sensors 202 are then provided to ananalog-to-digital (A/D) converter 206 for conversion into binary codethat can be processed by a processor 208.

[0022] Operation of the sensor drivers 204 is controlled through acamera control interface 210 that is in bi-directional communicationwith the processor 208. Also controlled through the interface 210 areone or more motors 212 that are used to control operation of the lenssystem 200 (e.g., to adjust focus, zoom, aperture, or shutter).Operation of the camera control interface 210 may be adjusted throughmanipulation of a user interface 214. The user interface 214 comprisesthe various components used to enter selections and commands into thecamera 102, 104 such as a shutter-release button and various controlbuttons provided on the camera.

[0023] The digital image signals are processed in accordance withinstructions from the camera control interface 210 and the imageprocessing system(s) 218 stored in permanent (non-volatile) devicememory 216. Processed images may then be stored in storage memory 220,such as that contained within a removable solid-state memory card (e.g.,Flash memory card).

[0024] As is depicted in FIG. 2, the external contact 106 is placed inelectrical communication with the processor 208 via an interfaceapplication specific integrated circuit (ASIC) 222. An exampleembodiment for this ASIC 222 is provided with reference to FIG. 3.

[0025]FIG. 3 is a schematic diagram of an embodiment for the interfaceASIC 222 identified in FIG. 2. As shown in FIG. 3, the ASIC 222 isconnected to the external contact 106 via a capacitor 300 so as toprovide capacitive coupling between the ASIC and the contact thatprotects the ASIC and the processor 208 (FIG. 2) from damage when thecontact is grounded or connected to a DC potential (e.g., throughunintended contact with a metal object). Additional protection isprovided by an electrostatic discharge (ESD) circuit 302 that divertsvoltage surges (whether negative or positive) away from the ASICcomponents using one or more protection diodes 304. If such a voltagesurge is positive, it is diverted to the V_(CC) node (indicated by “+”).If such a voltage is negative, it is diverted to ground.

[0026] The ASIC 222 further includes an output driver 306 that is usedto drive data to another device via the external contact 106. By way ofexample, the output driver 306 comprises a tristate driver that isconfigured to operate in three states, namely a first state in which alogical “1” is driven, a second state in which a logical “0” is driven,and a third state in which no values are driven. Toggling between eitherof the first two states and the third state may be achieved through useof an output enable signal (see FIG. 3). Such a configurationfacilitates the receipt of data (i.e., input data) with a comparatorcircuit 308 that is electrically connected to the output driver 306. Inthe embodiment shown in FIG. 3, the comparator circuit 308 includes acomparator 310 and a resistor 312. In use, input received from anotherdevice via the external contact 106 (when the output driver 306 isdisabled) is compared with a reference voltage V_(REF) so that the datacan be correctly interpreted. Note that the input is AC-coupled, and therestored DC voltage is provided through resistor 312. Thus, the receiveddata swings above and below reference voltage V_(REF). Comparator 308converts the analog waveform to binary data. Through such comparison,the input signal is cleaned and the data (i.e., “1s” and “0s”) itcontains may be identified. DC-free coding may be advantageously usedfor the data due to the AC-coupling of the circuit. This codingtechnology is well understood in the data storage and communicationsindustry. Note also that comparator 308 may add some hysteresis to itscomparison of the input to the reference voltage. This prevents randomnoise from being converted to data in the absence of an AC signal in.

[0027] In addition to the above-identified components, the ASIC 222further includes buffer memory 314 that is used to quickly cachereceived data to enable high data transfer rates.

[0028]FIG. 4 is a flow diagram illustrating an embodiment of a methodfor transferring data. In particular, FIG. 4 provides an overview of aprocess for transferring data from a first device to a second device. Itis noted that any process steps or blocks described in the flow diagramsof the present disclosure may represent modules, segments, or portionsof program code that includes one or more executable instructions forimplementing specific logical functions or steps in the process.Although particular example process steps are described, alternativeimplementations are feasible. Moreover, steps may be executed out oforder from that shown or discussed, including substantially concurrentlyor in reverse order, depending on the functionality involved.

[0029] Beginning with block 400, the first device is configured to senddata to the second device. The configuration involved may depend uponthe circumstances, but typically includes placing the first device in atransmit data mode in which the device is prepared to transmit data toanother device. Configuring the device to send data may further includeidentifying data that is to be transmitted using a device interface(e.g., display and control buttons). The manner in which dataidentification is achieved may depend upon the nature of the underlyingdevice that is sending the data. If the device comprises a camera, thedata (i.e., images) to be sent can be identified by the user, forexample, by scrolling through images stored in the camera (or itsremovable memory card) and tagging one or more images for transmission.Alternatively, identification may simply comprise scrolling throughimages until the image that is desired to be transmitted is shown in adisplay of the camera, thereby indicating an intent to transmit theimage.

[0030] In situations in which the device is not a camera (e.g., if thedevice is a PDA, mobile telephone, or notebook computer), identificationof data may be accomplished through more conventional means by, forinstance, scrolling through file directories and/or drop down menus andidentifying which of several listed files is/are to be transmitted.

[0031] Next, with reference to block 402, the external contacts of thefirst and second devices are touched together. This touching can beachieved by simply moving the devices toward each other until contact ismade between the contacts 106 as indicated in FIGS. 5A and 5B. As shownin FIG. 5B, the male contacts 106 may include a flat 500 thatfacilitates positive contact between the contacts when brought together.Moreover, the contacts 106 may be positioned so as to enable touching ofthe contacts of two devices when one or both of the devices are slidacross a smooth surface such as a table top (see FIGS. 5A and 5B).

[0032] Once the external contacts have been touched together, data istransferred from the first device to the second device, as indicated inblock 404. As is discussed in greater detail below, all data can betransferred in this manner even if the external contacts are touchedtogether for a brief period of time (e.g., a fraction of a second) dueto the great speed with which the data is transmitted. Moreover, alldata may be transferred even if the touching of the contacts is notperfectly continuous (i.e. the connection is noisy) due to the hightransmission speed and to the redundancy of transmission (describedbelow).

[0033]FIGS. 6A and 6B describe an embodiment of a method fortransmitting data from one device (i.e., a transmitting device) toanother device (i.e., a receiving device). In this example, thetransmitting device is assumed to be the first device 102 of FIG. 1A andthe receiving device is assumed to be the second device of that figure.In any case, however, data to be transmitted is identified by thetransmitting device, as indicated in block 600 of FIG. 6A. As describedabove with reference to FIG. 4, the data to be 5 transmitted may havefirst been identified by the user using some form of user interface(e.g., display, control buttons, etc.). In some embodiments, anindicator (e.g., indicator 108 in FIGS. 1A and 1B) is used to indicateto the user that the data to be transmitted has been identified andcurrently resides within the transmitting device. Such a condition isillustrated in FIG. 5A, which depicts the indicator 108 as beingilluminated.

[0034] Once the data has been identified, the transmitting devicedetects contact with the receiving device, as indicated in block 602,due to the user bringing the external contacts of the two devicestogether (see FIG. 5B). By way of example, touching of the externalcontacts may be detected by a “handshake” process. The transmittingdevice may begin periodically transmitting a “request to send” message,while listening for a return message from the receiving device. When thereceiving device recognizes the “request to send” once electricalcontact is made, it responds with a “ready to receive” message. When thetransmitting device recognizes the “ready to receive” message, thedevice is ready to send data.

[0035] After continuity between the two devices has been detected, thetransmitting device communicates with the receiving device via theexternal contacts, as indicated in block 604. These communicationscomprise any initial “handshaking” that is necessary to coordinate andmanage the transmission of data from the transmitting device to thereceiving device. Accordingly, such communications may comprise two-waycommunications in which the transmitting device queries the receivingdevice whether it is capable of and/or prepared to receive data, whatprotocols are to be used to transmit the data, the speed at which totransmit the data, and so forth.

[0036] The communications between the two devices can take severaldifferent forms. In one variant, a half-duplex communication scheme isused in which bi-directional communications are possible, but where suchcommunications are a sequence of one-way communications. In such acommunication scheme, the communication channel (i.e., the communicationpath comprising the external contacts) is treated like a one-way channeland the devices communicate with each other in an alternating fashion sothat only one device transmits at any given time. This alternative hasthe advantage of being a “baseband” method that does not requireextensive analog or RF circuitry.

[0037] In another variant, a full-duplex communication scheme is used inwhich contemporaneous bi-directional communications are possible. Such acommunication scheme may be implemented using a dual spectrum comprisingone forward channel frequency and one reverse channel frequency.Alternatively, spread spectrum technology such as code division multipleaccess (CDMA), time division multiple access (TDMA), frequency hopping,and so forth may be used. In yet a further variant, a simplexcommunication scheme is used in which only one device transmits to theother. In such a scheme, no feedback is provided to the transmittingdevice regarding the success, or failure, of the transmission.

[0038] Due to the initial communications described above, thetransmitting device can, as indicated in decision block 606, determinewhether the receiving device is prepared to receive transmitted data. Ifnot, data transfer cannot occur at this time, and flow is terminated forthis transfer session (FIG. 6B). If, on the other hand, the receivingdevice is prepared for data transfer, flow continues to block 608 atwhich the data to be transmitted is packetized by the transmittingdevice. Although packetization is not required, it is useful given thatthe connection between the external contacts is relatively noisy, i.e.perfectly continuous physical contact between the external contacts forthe duration of the data transmission may not be achieved because thecontacts are not configured for positive mating or interlocking.Accordingly, packetization is assumed in the embodiment of FIGS. 6A and6B.

[0039] Each data packet typically comprises a portion of the data (e.g.,one record of a file, or one tile of an image) to be transmitted as wellas information that is pertinent to the transmission and/orreconstruction of the transmitted data from the data packets. Suchinformation can be contained within a packet header and may include, forexample, a packet number. In such a case, the receiving device candetermine which packets did not arrive, or arrived in a corruptedcondition.

[0040] With reference next to block 610, one or more data packets aretransmitted from the transmitting device to the receiving device. Suchtransmission occurs at a very high data rate in that a direct link, asopposed to a wireless “connection,” is provided between the two devices.Therefore, bandwidth is not a constraint and data may be transmitted ina baseband scheme using relatively little power. Even assuming overheadof about 50% associated with packetizing the data and error correction,data rates of 100 megabits per second (mbps) or more are feasible. Insuch a case, a 1 megabyte (MB) image can be transmitted in under 0.2seconds. Therefore, individual files may be transmitted so quickly thattheir transmission appears nearly instantaneous from the perspective ofthe user. Notably, the buffer memory 314 facilitates such rapidtransmission in that input data may be quickly stored in the buffermemory as opposed to random access memory (RAM) and/or permanent memoryelsewhere in the device.

[0041] In bi-directional communication schemes (e.g., half orfull-duplex), one or more data packets may be transmitted and feedbackas to whether uncorrupted versions were received can be returned fromthe receiving device. Operation in this manner allows the transmittingdevice to determine which data packets must be retransmitted to thereceiving device.

[0042] With reference next to decision block 612 of FIG. 6B, thetransmitting device determines whether feedback in the form of an errornotification has been received from the receiving device, therebyindicating that one or more data packets were not received or were notreceived in proper condition. If not, i.e. if no such notification isreceived, flow continues down to decision block 618 described below. If,however, an error notification is received, flow continues to block 614.Such an error notification may comprise, for instance, a messagetransmitted from the receiving device to the transmitting deviceindicating that one or more particular packets were not properlyreceived. In such a case, the transmitting device retransmits one ormore packets to the receiving device to ensure that all transmittedpackets are properly received by the receiving device. At this point,the transmitting device can determine whether the error has beencorrected, as indicated in decision block 616. This determination ismade, for instance, in relation to messages transmitted by the receivingdevice to the transmitting device. If the error has not been corrected,the transmitting device can again retransmit data packets as indicatedin block 614. Assuming that the error is corrected, however, flowcontinues back to block 610 of FIG. 6A at which new data packets aretransmitted to the receiving device.

[0043] If no error notifications are received, flow continues todecision block 618 of FIG. 6B at which the transmitting devicedetermines whether all data packets that represent the data to betransmitted (e.g., file) have been transmitted. If so, flow for thetransmission session is terminated. When all data has been transmitted,the indicators provided on the transmitting and receiving devices may beused to indicate this condition to the user. For instance, as describedabove, an indicator 108 of the transmitting device may be illuminated toindicate to the user that the data to be transmitted resides on thetransmission device as shown in FIG. 5A. Once the data transmission iscompleted, however, this indicator 108 may be turned off and theindicator 108 of the receiving device may be turned on as shown in FIG.5B. In such an indication scheme, the indicators 108 represent orimitate movement of the data. Therefore, the user obtains the impressionthat the user can “see” the data pass from one device to the other,thereby providing highly intuitive feedback to the user as to thecompletion and success of the data transfer.

[0044] Returning to decision block 618, if one or more data packets havenot yet been transmitted, flow returns to block 610 of FIG. 6A and datapacket(s) is/are again transmitted to the receiving device. Flowcontinues from that point in the manner described above until all suchdata packets have been successfully transmitted.

[0045]FIG. 7 describes an embodiment of a method for receiving data thathas been sent from a transmitting device. In this embodiment, thereceiving device may comprise the second device 104 from FIG. 1A, andthe transmitting device may comprise the first device 102 from thatfigure. In any case, however, the receiving device communicates with thetransmitting device, as indicated in block 700 when an initialcommunication is sent by the transmitting device. As described abovewith reference to FIGS. 6A and 6B, the communications initially sentfrom the receiving device may pertain to any “handshaking” that isrequired and may contain information as to whether the receiving deviceis capable of and/or prepared to receive data, what protocols thereceiving device uses, the speed at which the receiving device canreceive data, and so forth.

[0046] Once these initial communications have been completed, thereceiving device receives data packets, as indicated in block 702.During this receipt of data packets, the receiving device monitors thedata transfer process to determine, as indicated in decision block 704,whether a transfer error is detected. By way of example, such an errorcomprises receipt of a corrupted data packet or failure to receive adata packet. If no such errors occur, flow continues down to decisionblock 708 described below. If an error does occur, however, flowcontinues to block 706 at which the receiving device requestsretransmission of any needed data packets. Once such a request is made,the receiving device again receives data packets (block 702).

[0047] Assuming that no transfer errors are detected or any such errorsare corrected, flow continues to decision block 708 at which it isdetermined whether all data packets have been received. Thisdetermination can be made, for instance, in relation to a “endtransmission” message received from the transmitting device, or inrelation to information received from the transmitting device as to howmany packets in total that are being sent. In either case, if allpackets have been properly received, flow is terminated. If not, flowreturns to block 702, and any remaining data packets are received.

What is claimed is:
 1. A method for transferring data from a firstdevice to a second device, comprising: configuring the first device tosend data; touching an external contact of the first device to anexternal contact of the second device; and transmitting data from thefirst device to the second device via the touching contacts.
 2. Themethod of claim 1, wherein configuring the first device comprisesplacing the first device in a transmit data mode.
 3. The method of claim1, wherein configuring the first device comprises identifying data to betransferred.
 4. The method of claim 1, wherein touching an externalcontact of the first device to an external contact of the second devicecomprises touching two contacts together for less than one second. 5.The method of claim 1, wherein touching an external contact of the firstdevice to an external contact of the second device comprises touchingtwo male contacts together.
 6. The method of claim 1, further comprisingturning off an indicator of the first device and turning on an indicatorof the second device to indicate to a user that the data has beentransferred from the first device to the second device.
 7. The method ofclaim 6, wherein turning off an indicator comprises turning off anilluminated light-emitting diode (LED) and wherein turning on anindicator comprises turning on a LED.
 8. A system for transferring data,comprising: a first device including a processor and an external contactin electrical communication with the processor; and a second deviceincluding a processor and an external contact in electricalcommunication with the processor, the external contact of the seconddevice being configured for making contact with the external contact ofthe first device for the purpose of transferring data between thedevices.
 9. The system of claim 8, wherein each external contact isprovided on a body of the devices.
 10. The system of claim 8, whereineach external contact is a male contact.
 11. The system of claim 8,wherein each external contact is formed as a metal nub.
 12. A system fortransferring data, comprising: a first device including a processor, anoutput driver in electrical communication with the processor, and anexternal contact in electrical communication with the output driver; anda second device including an external contact adapted to contact theexternal contact of the first device, a comparator circuit in electricalcommunication with the second device external contact, and buffer memoryin electrical communication with the comparator circuit.
 13. The systemof claim 12, wherein the output driver comprises a tristate driver. 14.The system of claim 12, wherein the comparator circuit comprises acomparator and a resistor.
 15. A system for transferring data,comprising: means for identifying data to be transferred; and means,exclusive of a cable or wireless communication component, fortransferring the identified data directly from one device to another.16. The system of claim 15, wherein the means for identifying datacomprise a user interface.
 17. The system of claim 15, wherein the meansfor transmitting comprise an external contact provided on a device thatis transmitting the data.
 18. The system of claim 17, wherein the meansfor transmitting further comprise an external contact provided on adevice that is receiving the data, both external contacts beingconfigured to make contact with each other.
 19. A device, comprising: aprocessor; an external contact that is provided on the exterior of thedevice, the external contact being configured to make contact with anexternal contact of a second device to facilitate transmission of datato the second device; and an interface that connects the processor andthe external contact.
 20. The device of claim 19, wherein the externalcontact is a male contact.
 21. The device of claim 19, wherein theexternal contact is formed as a metal nub.
 22. The device of claim 19,wherein the interface comprises an output driver.
 23. The device ofclaim 19, wherein the interface comprises a comparator circuit.
 24. Thedevice of claim 23, wherein the interface comprises buffer memory inelectrical communication with the comparator circuit.
 25. The device ofclaim 19, further comprising an electrostatic discharge (ESD) circuit.26. The device of claim 19, further comprising a capacitor providedbetween the external contact and the interface.
 27. The device of claim19, wherein the interface comprises an application specific integratedcircuit (ASIC).
 28. The device of claim 19, wherein the device is aportable device.
 29. The device of claim 19, wherein the device is adigital camera.
 30. A method for indicating transfer of data from onedevice to another, comprising: activating an indicator of a first deviceto indicate that data to be transferred resides in the first device;deactivating the indicator of the first device after the data has beentransmitted to a second device; and activating an indicator of thesecond device to indicate that the data now resides in the seconddevice.
 31. The method of claim 30, wherein activating an indicatorcomprises illuminating a light-emitting diode (LED).